The present invention relates to pressure sprayers and, more particularly, to portable, self-pumping pressure sprayers.
Pressure sprayers are well known in the art, having been developed many years ago. They essentially consist of a tank that is adapted to hold a liquid and become pressurized with air. The tank becomes pressurized via a pump. When a spray head and/or wand that is attached to the pressurized tank is opened, the liquid within the tank is ejected from the spray head/wand by the pressure in the tank. Eventually, the pressure within the tank decreases with the ejection of liquid therefrom. When the pressure against the liquid within the tank drops to a particular value, the liquid will not be ejected from the tank due to lack of pressure. Therefore, in order to maintain (have) adequate pressure within the tank in order to eject the liquid therefrom, the pressure must be periodically increased. This is accomplished by a manually actuated pump associated with the pressure sprayer.
Such pressure tanks may be used for spraying insecticides, pesticides, biocides, and herbicides, as well as paints, stains, water, and virtually any other non-viscous liquid. Small, portable (i.e. hand-carried) pressure tanks of one to five gallons in size have been used by the home and business industry. Early pressurized tanks were metal canisters with a manually actuated pump. When these metal tanks were filled with a liquid, and manually pumped to the appropriate pressure, they were quite heavy and cumbersome to carry. Currently, most pressure sprayers are formed from a suitable plastic. While plastic tanks are lighter than metal tanks when filled with a liquid and pumped to an adequate pressure, they are still cumbersome and somewhat heavy.
Wheels were added to larger pressure sprayers in order to alleviate the above problems by allowing a user to pull or push the pressure sprayer to its intended location rather than carry the pressure sprayer. These portable pressure sprayers were, however, still pressurized by manually actuated pumps. Thus, although these mobile pressure sprayers obviated the need to carry the heavy pressure sprayers, they were still pressurized by manual pumps.
Still another type of wheeled pressure sprayer in existence includes a pump which is actuated by rotation of the wheels of the sprayer. Upon actuation, the pump generates pressure which causes fluid to be sprayed out of the tank of the sprayer. However, this type of sprayer does not store pressure for spraying when the sprayer is not being moved (i.e. when the wheels are not being rotated). In other words, when movement of the sprayer is stopped so that the wheels are no longer rotating, the sprayer stops pumping fluid from the tank of the sprayer to the environment (e.g. onto a lawn).
What is needed is a portable pressure sprayer that develops its own pressure for ejecting a liquid and stores such pressure for later use by the sprayer even when the wheels of the sprayer are no longer being rotated.
What is further needed is a portable pressure sprayer that develops it own pressure for ejecting a liquid wherein adequate ejection pressure is maintained at least transiently.
What is still further needed is a portable pressure sprayer that develops pressure for ejecting a liquid through movement of the pressure sprayer, wherein adequate pressure is maintained for liquid ejection during periods of non-movement (i e. during periods when the wheels of the sprayer are no longer being rotated).
The present invention is a self-energizing pressure sprayer in which movement of the sprayer creates and maintains adequate pressure to expel an amount of liquid held therein during both movement and non-movement of the sprayer.
In one form thereof, a pressure sprayer having a holding tank includes a pressure pump that is adapted to pump a liquid from the holding tank to the accumulator during movement of the sprayer (i.e. rotation of the wheels of the sprayer).
In another form thereof, a pressure sprayer includes a holding tank, an accumulator and a pressure pump in communication with the holding tank and the accumulator. The pressure sprayer further includes wheels carried on an axle that rotates during pushing and/or pulling movement of the pressure sprayer. The pressure pump is associated with the axle such that rotation of the axle causes the pressure pump to pump fluid from the holding tank to the accumulator wherein the fluid is pressurized for ejection from the sprayer even at times when the wheels of the sprayer are being maintained stationary.
In yet another form thereof, a pressure pump of a pressure sprayer having a holding tank and an accumulator both in fluid communication with the pressure pump, is coupled to a cam assembly affixed on an axle for wheels of the pressure sprayer that drives the pressure pump during pushing and/or pulling movement of the pressure sprayer. The pump is in communication with a tank adapted to hold a liquid to be ejected and a pressure accumulator. During movement of the pressure sprayer, the cam assembly rotates to cause the pressure pump to reciprocate and thus pump (operate). Once the pressurized fluid has been depleted, movement of the pressure sprayer re-energizes (re-pressurizes) fluid for ejection.
According to still another embodiment of the present invention, there is provided a pressure sprayer which includes a tank for holding fluid, and an accumulator for storing fluid therein under pressure. The sprayer further includes a number of wheels for supporting the tank. Moreover, the sprayer includes a pump which advances fluid from the tank into the accumulator in response to rotation of the number of wheels. The pressure within the accumulator is increased when fluid is advanced into the accumulator by the pump.
Yet in accordance with another embodiment of the present invention, there is provided a pressure sprayer which includes an accumulator for storing fluid therein under pressure, and at least one wheel which rotates when the pressure sprayer is moved. The sprayer also includes a pump which advances fluid into the accumulator in response to rotation of the at least one wheel. An increased pressure is generated within the accumulator in response to fluid being advanced into the accumulator by the pump. Further, the increased pressure within the accumulator is maintained when the at least one wheel is stationary.
In accordance with still another embodiment of the present invention, there is provided a method of spraying fluid with a portable pressure sprayer having a tank, an accumulator, and a number of wheels. The method includes the steps of (i) moving the portable pressure sprayer so as to cause the number of wheels to rotate, (ii) advancing fluid from the tank into the accumulator in response to rotation of the number of wheels, (iii) generating an increased pressure within the accumulator in response to fluid being advanced into the accumulator, and (iv) maintaining the increased pressure within the accumulator after the moving step when the number of wheels are stationary.
In accordance with yet another embodiment of the present invention, there is provided a method of spraying fluid with a pressure sprayer having at least one wheel. The method includes the step of moving the portable pressure sprayer so as to cause the at least one wheel to rotate. The method also includes the step of generating an increased pressure within the sprayer in response to rotation of the at least one wheel. In addition, the method includes the step of maintaining the increased pressure within the sprayer after the generating step when the at least one wheel is stationary.